Everything I have read so far about Redgard tells me that it is a great product when used on shower or sauna floors, I have not read anything that indicates that it can (or cannot) be used on walls for as a water barrire before tiling walls. My question is - can I/should I put Regard on top of Hardibacker before I tile my tub/shower walls?

Six months ago I asked the same question, about any old liquid membrane that you can either roller on, paint on or trowel on. And nobody answered. But later I read here in many posts about people doing it that way. Redgard, Mapei HPG, whatever. There are differences, and I don't know enough to describe them. I do 'know' from reading here that Redgard is prolly the best because people use it for steam shower wallls, and the Redgard manufacturer warrants it for (residential) steam shower walls too. Steam applications are the toughest in terms of vapor pressure. Hope this helps.

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David.
"Do a search, find out what you can, and come back with more questions."
"...slower than the average DIYer

I will definitely use a modified thinset, however I get the impression from your reply that using the Redgard is an overkill and not necessary for the walls of a normal tub/shower combo.

Just to be real sure - I do not have a vapor barrier behind the Hardibacker board so thats why I thought I should play it safe and put the Redgard on the Hardibacker and then the tiles on top of the Redgard using the modified thinset.

I suppose my main concern is - Will the tiles stay attached to the Redgard (hardibacker, Redgard, modfied thinset and then tiles) even with a modified thinset?

If this is really an overkill or there is some doubt if the tiles will hold, I will return the Redgard and save the $.

Neil - look at my thread (do a search on "shawn's" and you'll come up with it.) I used RedGuard in my bath. I did the shower walls, the ceiling and the edge of the flooring. You can see pictures of it.

As a note - I DID have it on my CEILING and I tiled that as well. The tiles stuck with no problem at all. I think you'll be fine. And although the stuff is pricey - I do NOT think it is overkill. Money well spent for peace of mind.

Water leaking through walls is NOT a problem I want to deal with. Not in any shape or form!

Paint on acrylic waterproofing is pretty much the standard here in NZ and Australia. As long as you follow the manufacturers directions you shouldn't have a worry. The most common problem is that some tilers start putting tile up before the membrane is fully cured, or the membrane is put on far too thin (and therefore cannot accomodate movement). As others have said, use a modified thinset and you're good to go. BTW nothing wrong with overkill in a wet area.

Like everyone says..that's fine,especially since you don't have the vapor barrier.We tend to answer things differently,for different questions...a lot of things to consider...some people have already spent a lot on materials,and such and i tend to not force them to spend more,and also when we're answering a lot, we tend to hurry and not give lengthy answers,and we have to take into consideration the perceived skill levels of some..not meaning you...but some diy will tend not to do a step right which will cause a failure, and we gear answers accordingly sometimes....then sometimes we miss you all together.

A week ago I got a lot of useful tips (from this site) about using Redgard on top of Hardibacker. Now it's come time to tile and while l was laying out the reference lines etc I pulled off a piece of Blue tape attached to the bath and a splash of Redgard. I ended up easily pulling up a small peice of the Redgard attatched to the Hardibacker, I pulled a little more and now have a 9" tear in the Redgard!!!!

Now I am really worried if I can easily pull the Redgard away from the Hardibacker by hand I am sure my tiles will just fall off the wall (Modified thinset or not) .

Is this Redgard stuff any use at all, I want rip it all off an apply the tiles directly to the hardibacker any thoughts - HELP????